This invention relates to a circular knitting machine, in particular for hose knitting, with continuous cycle lubrication.
Hose knitting machines are known wherein lubrication of the main members such as gears, needles, needle cylinder, cylinder holder, is accomplished by means of dispensing nozzles fed from metering devices located in the proximity of these surfaces which require lubrication and operated as required by a machine control. These dispensing nozzles can be connected to one or more pumps and are actuated either individually or in sets according to the machine operating conditions.
As the knitting rate of these machines increases, the lubrication provided by such devices has shown a number of drawbacks. In order to dissipate the heat generated, on account of the friction, it is necessary to pump an increasingly larger amount of oil. In particular in connection with the needle cylinder, the needles and respective flutes wherein they slide must be sprinkled continuously to simultaneously provide an effective lubrication and good removal of heat. The high speed of the needle cylinder resists, however, the contact of the oil with the mechanical members to be lubricated in that, owing to the centrifugal force, the oil is thrown outwards almost instantaneously.
To obviate this drawback, highly viscous oils have been tried unsuccessfully because a lower heat removal is obtained.